Counterfeiting poses a serious problem to the pharmaceutical, cosmetics, electronics, software, automotive and aircraft industries, to name a few. Counterfeit products can lead to lost revenues, increased liability, and brand erosion. Product recalls due to counterfeit warnings can be expensive and disruptive.
Overt measures to deter counterfeiting include marking products with distinct colors and patterns, holograms, recto/verso registration, and visible watermarks. Covert measures include marking products with invisible marks and machine readable code, fluorescent and magnetic inks, hidden patterns, encrypted codes, radio frequency identification, engravements, and micro-displacement of glyphs.
Most of these measures add complexity or cost (or both) to product manufacture. In addition, detection can be difficult and slow. Detection using some of these measures involves specialized equipment.
An inexpensive anti-counterfeiting measure is desirable.
In certain situations, quick detection is essential. An inspector might have to enter a store and determine whether the goods being sold are counterfeit. If the inspector draws attention, his life could be at risk.